From: Hans HübnerSep 10, 2012 (OP of that G+ post)
I have not looked into OpenGL, but it'd certainly be good to have a faster way to draw on the screen. VECTO and bitmap copying is not suitable for anything that is supposed to move.
This is my experience as well. You can mmap /dev/fb0 and draw on it, and you can use something like directfb or even Cairo if you're not into lisp, but if you want to do even trivial 2D acceleration you are out of luck.
Re-rasterizing and blitting the whole screen on every change is clearly unacceptable, but there's a large gap between that and outright HW acceleration. Being smarter about redraws gets you a long way. I have used things like web browsers on unaccelerated X11, and it's been totally usable even on ARM.
But apart from educational purposes, why would you do that? Sure, the graphics driver is an ugly blob, but if you care that much about libre hardware/software, it would be odd buying an Raspberry Pi in the first place.
Granted, "for educational reasons" is a valid subject for the Pi. Get that old Abrash book out and let the OpenGL-spoiled kids feel the pain.
I have not looked into OpenGL, but it'd certainly be good to have a faster way to draw on the screen. VECTO and bitmap copying is not suitable for anything that is supposed to move.
This is my experience as well. You can mmap /dev/fb0 and draw on it, and you can use something like directfb or even Cairo if you're not into lisp, but if you want to do even trivial 2D acceleration you are out of luck.